Sleeping in two short naps is not going to provide any athletic benefits. As already mentioned, you very likely will not get enough deep sleep. Do a search on sleep levels and you should find plenty of information on how we sleep. The short synopsis is that sleep is required more for mental reasons than physical. When you sleep, there is much going on in your brain, a lot of which we don't fully understand. We do know that we need certain amounts of the deepest levels of sleep in order to be fully rested. The best way to get qulity sleep is simply do what's natural and get a good night's rest.